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From Sean Rowe <ichabo...@gmail.com>
Subject Re: jndi question
Date Tue, 23 Aug 2005 16:02:09 GMT
The first post on this included the server.xml, and further down in the 
page is the relevant part of web.xml ( i just double checked that ).  as 
for context.xml, i have listed it in my webapp.xml file, as well as 
server.xml as all other examples have suggested.  i then tried it in the 
admin module, where it then put it in server.xml for me.  i'm willing to 
try anything at this point, though, if you have any suggestions.

as for my post not being jndi specific, i applogize if that's the case.  
i'm not really familiar with jndi....but when I did a search for 
'connection pooling', jndi seemed to be what everyone suggested i use.  
what i want to do, if it's not clear, is to create a connection pool to 
my MySql database. 

thanks,
sean

Brian Cook wrote:

>
> Actually the files I listed are NOT in the first post.  It shows the 
> server.xml and the code calling it but does not show web.xml or 
> context.xml.
>
> The error you are getting just means that that the JNDI resource being 
> called in the code is not defined in both web.xml and context.xml.
>
> In looking at the code snip it in the first post I am not following 
> what you are trying to do.  The post is for a JNDI question but in the 
> code it looks like you are calling the DB URL directly.  The whole 
> point of JDNI being to get specific URL, and configuration info 
> outside of the code base.  I am not following what it is you are 
> trying to do here.
>
>
>
> Sean Rowe wrote:
>
>> Brian, thank you for replying.  I was afraid my topic was dead.  If 
>> you could look at my first post, I listed all the files that you have 
>> suggested I take a look at.  I have done everything you have 
>> suggested, but am still getting errors.  The error I am getting now is
>>
>> javax.naming.NameNotFoundException: Name java:comp is not bound in 
>> this Context
>>
>> I can't find anything on the net or in any books I've looked at that 
>> explains this.  As far as I can tell, java:comp should just be 
>> there.  Any ideas?  Thanks again.
>>
>> Sean
>>
>> Brian Cook wrote:
>>
>>>
>>> Yes you can use JNDI with out using JSTL.  But the only way to 
>>> configure it is to define the JNDI resources in the web.xml and 
>>> context.xml files.    Technically you should be able to use the 
>>> globally defined JNDI resources in server.xml, and I have seen 
>>> configuration set ups doing it when googling.  But could never get 
>>> them to work.
>>>
>>> This highlights another area of seemingly unneeded complication in 
>>> Java/Unix development.  Using JNDI for data sources which was 
>>> supposed to help you save time requires that you redundantly define 
>>> the JNDI resource in at lest 2 if not 3 places.
>>>
>>> The admin tool which was also supposed to help save time defines the 
>>> JNDI resources in server.xml which does not really seem to be all 
>>> that helpful.  I am sure there is likely a reason for this but I am 
>>> ignorant of it.  The admin tool is also supposed to let you define 
>>> JNDI resources  per context but it errors out when ever I have tried 
>>> it.
>>>
>>> My experience with the Tomcat Admin and Manager tools is that they 
>>> are worthless.  Of the few steps they try to help with more often 
>>> that not they just return errors when you need to use it.  I removed 
>>> them both and have gone back to doing set ups manually and there has 
>>> not been much of a time difference doing it this way.
>>>
>>> Any way for JNDI to work you will have to add the definition for it 
>>> in both web.xml and context.xml in the <<Tomcat 
>>> Folder>>/conf/Catalina/localhost/ folder.  This seems counter 
>>> productive since it makes your app less portable having the data 
>>> base configuration details inside the context and by extent the WAR 
>>> file but it is what you have to do to get it to work right now.
>>>
>>> I feel your pain I know it is frustrating spending hours debugging 
>>> just the DB connection but todate that is the reality of Java web 
>>> app development.  It is why I fear we will all be .Net developers 
>>> some day.
>>>
>>>
>>> Example :
>>> http://jakarta.apache.org/tomcat/tomcat-5.5-doc/jndi-resources-howto.html 
>>>
>>>
>>> <CODE>
>>>
>>> Context initCtx = new InitialContext();
>>> Context envCtx = (Context) initCtx.lookup("java:comp/env");
>>> DataSource ds = (DataSource)
>>>   envCtx.lookup("jdbc/EmployeeDB");
>>>
>>> Connection conn = ds.getConnection();
>>> ... use this connection to access the database ...
>>> conn.close();
>>>
>>> </CODE>
>>>
>>>
>>>
>>>
>>>
>>> <WEB.XML>
>>>
>>> <resource-ref>
>>>   <description>
>>>     Resource reference to a factory for java.sql.Connection
>>>     instances that may be used for talking to a particular
>>>     database that is configured in the server.xml file.
>>>   </description>
>>>   <res-ref-name>
>>>     jdbc/EmployeeDB
>>>   </res-ref-name>
>>>   <res-type>
>>>     javax.sql.DataSource
>>>   </res-type>
>>>   <res-auth>
>>>     Container
>>>   </res-auth>
>>> </resource-ref>
>>>
>>> </WEB.XML>
>>>
>>>
>>>
>>>
>>> <CONTEXT FILE>
>>>
>>> <Context>
>>>
>>>   <Resource     name="jdbc/EmployeeDB"
>>>         auth="Container"
>>>                 type="javax.sql.DataSource"
>>>         username="dbusername"
>>>         password="dbpassword"
>>>                 driverClassName="org.hsql.jdbcDriver"            
>>> url="jdbc:HypersonicSQL:database"
>>>         maxActive="8"
>>>         maxIdle="4"/>
>>>
>>> </Context>
>>>
>>> </CONTEXT FILE>
>>>
>>>
>>>
>>>
>>>
>>>
>>> Sean Rowe wrote:
>>>
>>>> Dirk, I'm sorry I didn't see the difference on the page you sent me 
>>>> to.  However, if there is a way I can do this without having to use 
>>>> jstl, I would really like to know.  I was hoping to put the code in 
>>>> a class somewhere that my servlets could use.
>>>>
>>>> thanks,
>>>> sean
>>>>
>>>> Dirk Weigenand wrote:
>>>>
>>>>> Sean,
>>>>>
>>>>>  
>>>>>
>>>>>> --- Urspr√ľngliche Nachricht ---
>>>>>> Von: Sean Rowe <ichabooka@gmail.com>
>>>>>> An: Tomcat Users List <tomcat-user@jakarta.apache.org>
>>>>>> Betreff: Re: jndi question
>>>>>> Datum: Mon, 22 Aug 2005 09:24:10 -0500
>>>>>>
>>>>>> Thanks for responding Dirk.  I've practically memorized the 
>>>>>> documentation on the link you sent:
>>>>>>
>>>>>> // Obtain our environment naming context
>>>>>> Context initCtx = new InitialContext();
>>>>>> Context envCtx = (Context) initCtx.lookup("java:comp/env");
>>>>>>
>>>>>> // Look up our data source
>>>>>> DataSource ds = (DataSource)
>>>>>>  envCtx.lookup("jdbc/EmployeeDB");
>>>>>>
>>>>>> // Allocate and use a connection from the pool
>>>>>> Connection conn = ds.getConnection();
>>>>>> ... use this connection to access the database ...
>>>>>> conn.close();
>>>>>>
>>>>>> Whenever I try this, here's what I get (which led me to trying it

>>>>>> the way
>>>>>> I posted):
>>>>>>
>>>>>> javax.naming.NameNotFoundException: Name java:comp is not bound 
>>>>>> in this
>>>>>> Context
>>>>>>
>>>>>>   
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> No. Did you look at
>>>>> http://jakarta.apache.org/tomcat/tomcat-5.5-doc/jndi-datasource-examples-howto.html?

>>>>>
>>>>>
>>>>> I recommend putting the context definition in its own content.xml. On
>>>>> redeploying my application tomcat wouldn't find the driver class 
>>>>> anymore.
>>>>>
>>>>> Mind you not the class itself but the definition of what class to 
>>>>> load.
>>>>>
>>>>> This problem was solved by putting the context into context.xml.
>>>>>
>>>>> regards
>>>>>       Dirk
>>>>>
>>>>>  
>>>>>
>>>>
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